1. Field of the Invention
This invention relates to a protective sheet used for packaging photosensitive sheets, such as X-ray photographic films, lithfilms, cut films, photographic papers, PS sheets and photosensitive resin films.
2. Description of the Prior Art
The photosensitive sheets described above are usually protected by a pad in order to prevent nicking at the time of insertion into the bag in which they are packaged, at the time of transportation and at the time of use in order to protect the sheets from being struck during transportation. A conventional pad 1 was a U-shaped corrugated board, as shown in FIG. 10, and superposed tens to hundreds of photosensitive sheets 2 were placed therein, and inserted into a bag 3 (e.g. Japanese Utility Model KOKAI No. 40535/1981). Another conventional pad 1 was, as shown in FIG. 11, a shallow box-shaped corrugated board where one side and a half upper face were opened. However, the pad of FIG. 10 had the defect that, when the photosensitive sheets were slippery, they slipped out of the pad to cause packaging troubles. The pad of FIG. 11 did not have such a defect. However, construction required time and was expensive.